use anyhow::Result;
use serde::{Deserialize, Serialize};
use tracing::info;

use super::server::{McpRequest, McpResponse};

/// MCP client for connecting to external MCP servers
#[derive(Debug)]
pub struct McpClient {
    endpoint: String,
    is_connected: bool,
    client: reqwest::Client,
}

/// Client configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ClientConfig {
    pub endpoint: String,
    pub timeout_seconds: u64,
    pub retry_attempts: u32,
}

impl McpClient {
    /// Create a new MCP client
    pub async fn new(endpoint: &str) -> Result<Self> {
        info!("Creating MCP client for endpoint: {}", endpoint);
        
        let client = reqwest::Client::builder()
            .timeout(std::time::Duration::from_secs(30))
            .build()?;
        
        Ok(Self {
            endpoint: endpoint.to_string(),
            is_connected: false,
            client,
        })
    }
    
    /// Connect to the MCP server
    pub async fn connect(&mut self) -> Result<()> {
        info!("Connecting to MCP server: {}", self.endpoint);
        
        // TODO: Implement actual connection logic
        // This would involve establishing WebSocket or HTTP connection
        
        self.is_connected = true;
        Ok(())
    }
    
    /// Disconnect from the MCP server
    pub async fn disconnect(&mut self) -> Result<()> {
        info!("Disconnecting from MCP server");
        
        self.is_connected = false;
        Ok(())
    }
    
    /// Check if client is connected
    pub fn is_connected(&self) -> bool {
        self.is_connected
    }
    
    /// Send a request to the MCP server
    pub async fn send_request(&self, request: &McpRequest) -> Result<McpResponse> {
        if !self.is_connected {
            return Err(anyhow::anyhow!("Client not connected"));
        }
        
        info!("Sending MCP request: {}", request.method);
        
        // TODO: Implement actual request sending
        // This is a placeholder implementation
        
        let response = McpResponse {
            id: request.id.clone(),
            result: Some(serde_json::json!({
                "status": "success",
                "message": "Request processed"
            })),
            error: None,
        };
        
        Ok(response)
    }
    
    /// List available tools on the server
    pub async fn list_tools(&self) -> Result<Vec<serde_json::Value>> {
        let request = McpRequest {
            id: uuid::Uuid::new_v4().to_string(),
            method: "tools/list".to_string(),
            params: serde_json::json!({}),
        };
        
        let response = self.send_request(&request).await?;
        
        if let Some(result) = response.result {
            if let Ok(tools) = serde_json::from_value::<Vec<serde_json::Value>>(result) {
                return Ok(tools);
            }
        }
        
        Ok(vec![])
    }
    
    /// Call a tool on the server
    pub async fn call_tool(&self, tool_name: &str, params: serde_json::Value) -> Result<serde_json::Value> {
        let request = McpRequest {
            id: uuid::Uuid::new_v4().to_string(),
            method: "tools/call".to_string(),
            params: serde_json::json!({
                "name": tool_name,
                "arguments": params
            }),
        };
        
        let response = self.send_request(&request).await?;
        
        if let Some(error) = response.error {
            return Err(anyhow::anyhow!("Tool call failed: {}", error.message));
        }
        
        Ok(response.result.unwrap_or_default())
    }
    
    /// Ping the server
    pub async fn ping(&self) -> Result<bool> {
        let request = McpRequest {
            id: uuid::Uuid::new_v4().to_string(),
            method: "ping".to_string(),
            params: serde_json::json!({}),
        };
        
        match self.send_request(&request).await {
            Ok(_) => Ok(true),
            Err(_) => Ok(false),
        }
    }
    
    /// Get server information
    pub async fn get_server_info(&self) -> Result<serde_json::Value> {
        let request = McpRequest {
            id: uuid::Uuid::new_v4().to_string(),
            method: "initialize".to_string(),
            params: serde_json::json!({
                "protocolVersion": "2024-11-05",
                "capabilities": {
                    "tools": {}
                },
                "clientInfo": {
                    "name": "CDB Studio",
                    "version": env!("CARGO_PKG_VERSION")
                }
            }),
        };
        
        let response = self.send_request(&request).await?;
        Ok(response.result.unwrap_or_default())
    }
}

impl Default for ClientConfig {
    fn default() -> Self {
        Self {
            endpoint: "http://localhost:8080".to_string(),
            timeout_seconds: 30,
            retry_attempts: 3,
        }
    }
}
